The present invention relates to a method of measuring light reflections of an object, a light-source illumination-observation assembly, a diffuser light-source assembly, an apparatus for measuring light reflections of an object comprising such a light-source illumination-observation assembly, such an apparatus further comprising a diffuser light-source assembly, and use of such an apparatus for measuring reflection, retroreflection, or both, preferably the object being a reflective material, a reflective device, a retroreflector material, and a retroreflector device, or a combination thereof, in particular a road marking, a road surface, a raised pavement marking, or all.